Creating a digital dental model of a patient&#39;s teeth using interproximal information

ABSTRACT

Creating a digital tooth model of a patient&#39;s tooth using interproximal information is provided. Interproximal information is received that represents a space between adjacent physical teeth of the patient. A digital teeth model of a set of physical teeth of the patient that includes the adjacent physical teeth is received. One or more digital tooth models is created that more accurately depicts one or more of the physical teeth than the corresponding digital teeth included in the digital teeth model based on the interproximal information.

RELATED APPLICATION SECTION

This application is a continuation of U.S. patent application Ser. No.13/786,300, filed on Mar. 5, 2013, now U.S. Pat. No. 10,617,489, issuedApr. 14, 2020, which claims priority to and benefit of Provisional U.S.Patent Application No. 61/739,600, filed on Dec. 19, 2012 entitled“CREATING A DIGITAL DENTAL MODEL OF A PATIENT'S TEETH USINGINTERPROXIMAL INFORMATION” by Grove et al., and assigned to the assigneeof the present application.

This application is related to co-pending U.S. patent application Ser.No. 13/719,823 filed on Dec. 19, 2012 entitled “APPARATUS AND METHOD FOROPTICALLY SCANNING AN OBJECT IN REGISTRATION WITH A REFERENCE PATTERN”by Kuo, assigned to the assignee of the present application and to theextent not repeated herein, the contents of this related patentapplication are hereby incorporated herein by reference.

This application is related to U.S. Patent Application No. 61/739,450filed on Dec. 19, 2012 entitled “METHODS AND SYSTEMS FOR DENTALPROCEDURES” by Kopelman, assigned to the assignee of the presentapplication and to the extent not repeated herein, the contents of thisrelated patent application are hereby incorporated herein by reference.

This application is related to co-pending U.S. patent application Ser.No. 13/787,634 filed on Mar. 6, 2013, entitled “METHODS AND SYSTEMS FORDENTAL PROCEDURES” by Kopelman, which claims priority to U.S. PatentApplication No. 61/739,450 filed on Dec. 19, 2012 entitled “METHODS ANDSYSTEMS FOR DENTAL PROCEDURES” by Kopelman, assigned to the assignee ofthe present application.

BACKGROUND

Orthodontic treatments involve repositioning misaligned teeth andimproving bite arrangements for improved cosmetic appearance and dentalfunction. Conventionally, repositioning of teeth has been accomplishedby what are commonly referred to as “braces.” Braces comprise a varietyof elements such as brackets, bands, archwires, ligatures, and O-rings.After some of these elements are bonded to the teeth, periodicappointments with the treating doctor are required to adjust the braces.This involves bending or installing different archwires having differentforce-inducing properties, and/or replacing ligatures and O-rings.

An alternative to braces includes the use of elastic positioning dentalappliances (also known as “aligners”) for repositioning teeth. Such anappliance can be comprised of a thin shell of elastic material thatgenerally conforms to a patient's teeth but each appliance to be used ata treatment stage has a cavity geometry that is slightly out ofalignment with the teeth arrangement at the start of that treatmentstage. Placement of the elastic positioning dental appliance over theteeth applies controlled forces in specific locations to gradually movethe teeth into a new arrangement as defined by the cavity of theappliance. Repetition of this process moves the teeth through a seriesof intermediate arrangements to a final desired arrangement. Due to thelimited space within the oral cavity and extensive movements that someteeth typically undergo as a part of treatment, the teeth will often bemoved throughout the series of intermediate tooth arrangements toproperly arrange the teeth. Thus, a single patient treated with elasticpositioning dental appliance may experience from 2 to perhaps 50 or morealigner stages (with an average of 25-30 aligner stages per arch) beforeachieving the final desired teeth arrangement.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part ofthis Description of Embodiments, illustrate various embodiments of thepresent invention and, together with the description, serve to explainprinciples discussed below:

FIG. 1 illustrates an example of a patient's physical teeth, accordingto one embodiment.

FIG. 2 illustrates an example of a digital teeth model that representsthe patient's set of physical teeth, according to one embodiment.

FIG. 3 illustrates an example of a conventional three dimensional (3D)virtual model that was created based on a digital teeth model, accordingto one embodiment.

FIG. 4 illustrates the use of an instrument to measure an interproximalspace between adjacent physical teeth, according to one embodiment.

FIG. 5 illustrates an example of a user interface, according to oneembodiment.

FIG. 6 illustrates an example of created digital tooth models, accordingto one embodiment.

FIG. 7 illustrates a system for creating a digital tooth model of apatient's tooth using interproximal information, according to oneembodiment.

FIG. 8 illustrates a method of creating a digital tooth model of apatient's tooth using interproximal information, according to oneembodiment.

FIGS. 9 a-9 f depict scannable objects that can be inserted betweenadjacent physical teeth and used as a part of determining interproximalinformation that represents a space between the adjacent physical teeth,according to various embodiments.

FIGS. 10 a-10 c depict scannable objects inserted between adjacentphysical teeth, according to various embodiments.

FIG. 11 depicts a digital tooth that represents one tooth that may beused to match or closely approximate the position of a correspondingtooth, according to one embodiment.

FIGS. 12A and 12B depict an example of a patient's physical teeth atvarious stages of position as a part of performing interproximalreduction, according to various embodiments.

The drawings referred to in this Brief Description should not beunderstood as being drawn to scale unless specifically noted.

DESCRIPTION OF EMBODIMENTS

Reference will now be made in detail to various embodiments of thesubject matter, examples of which are illustrated in the accompanyingdrawings. While various embodiments are discussed herein, it will beunderstood that they are not intended to limit to these embodiments. Onthe contrary, the presented embodiments are intended to coveralternatives, modifications and equivalents, which may be includedwithin the spirit and scope of the various embodiments as defined by theappended claims. Furthermore, in the following Description ofEmbodiments, numerous specific details are set forth in order to providea thorough understanding of embodiments of the present subject matter.However, embodiments may be practiced without these specific details. Inother instances, well known methods, procedures, components, andcircuits have not been described in detail as not to unnecessarilyobscure aspects of the described embodiments.

Unless specifically stated otherwise as apparent from the followingdiscussions, it is appreciated that throughout the description ofembodiments, discussions utilizing terms such as “receiving,”“accessing,” “creating,” “depicting,” “specifying,” “obtaining,”“representing,” “corresponding,” “including,” “identifying,” “removing,”“moving,” “determining,” or the like, refer to the actions and processesof a computer system, data storage system, storage system controller,microcontroller, processor, or similar electronic computing device orcombination of such electronic computing devices. The computer system orsimilar electronic computing device manipulates and transforms datarepresented as physical (electronic) quantities within the computersystem's/device's registers and memories into other data similarlyrepresented as physical quantities within the computer system's/device'smemories or registers or other such information storage, transmission,or display devices.

Various methods can be used for creating digital teeth models that canbe used for record keeping/visualization, restorative or orthodonticpurposes. One of the orthodontic purposes which digital teeth models canbe used is to help create dental appliances for correcting the positionof a patient's teeth. One method involves making a three dimensional(3D) virtual model of the patient's physical teeth. The threedimensional virtual model can be based on a digital directly orindirectly of a patient's teeth such as directly by an intraoral scan orother direct scan of a patient's physical teeth or indirectly based on ascan of a manually obtained impression of the patient's physical teethor a scan of a model made from a manually obtained impression of thepatient's physical teeth. All of these are collectively referred to as adigital scan. One or more elastic positioning dental appliances can befabricated from digital data that is created based on the threedimensional virtual model.

Frequently a patient's physical teeth have interproximal spaces betweenthem—either naturally occurring or intentionally created by thedoctor—which a fully successful course of treatment will close,significantly reduce or even enlarge (as in the case for making spacefor restorative dental treatments). Typically, an interproximal spacebetween two adjacent physical teeth that is smaller than approximately0.25 millimeters (mm) may be too small to be represented in a digitalscan obtained, for example, as set out in paragraph (18).

Therefore, the interproximal space may not be properly represented in aconventional three dimensional (3D) virtual model that is created basedon the digital scan. The digital teeth in a conventional threedimensional (3D) virtual model that correspond to the adjacent physicalteeth may appear to be connected, i.e. have no interproximal space.Various embodiments are provided for creating one or more digital toothmodels that more accurately depict one or more physical teeth based oninterproximal information that represents an interproximal space as apart of more successfully reducing or closing an interproximal space.

In situations where an interdental space is present, the space may besufficiently small whereby the accurate reproduction of the pre-existingspace in a dental model of the teeth may be difficult or impossible.These spaces may be naturally occurring or artificially introducedthrough orthodontic treatment, for example, or through mechanical meanssuch as a dental procedure whereby the teeth are reshaped.

For example, in situations where dental crowding is present, or whencertain teeth are not the correct/desired shape, recontouring of theteeth may be desirable (also called “interproximal reduction” or “IPR”for short). This can be accomplished through any number of dentalinstruments, including abrasive strips, discs, and/or burs. The resultis that the teeth are narrowed and the resulting space in between theteeth is known as an interproximal space. An interproximal space mayalso be created by orthodontically moving adjacent teeth away from eachother.

Depending on if the gum tissue, which normally occupies the undercutbetween adjacent teeth is present (also known as a papilla), theinterproximal space may either be a vertical space with relativelyuniform width from the occlusal-most portion of the contact to the gums,or in the case of missing papilla, a vertical space at the occlusal-mostportion of the contact which opens up into a triangular space near thegum line due to the undercuts of the adjacent teeth and the missingpapilla.

When small spaces are created, for example width-wise, or if teeth areobstructing the space due to crowding arrangements, trying to accuratelydetermine the dimensions of the space using scans or impressions of theteeth can be particularly challenging. This is because in order for thedimensions to be accurately captured, the impression material needs toflow in between the teeth and not be torn upon removal of theimpression. If the material which flows in between the teeth becomestorn, then the resulting model of the teeth will appear as if the teethare actually touching, when in fact, a space is present in between.

For digital scans of the teeth, small spaces may be difficult toaccurately capture because the scan is unable to properly characterizethe areas where a direct line of sight cannot be obtained as a result ofobstruction from the tooth structure being scanned.

Therefore, according to one embodiment, a way to accurately capture thewidth and shape of the interproximal spaces (if any) is provided so thatwhat is present in the mouth of the patient can be more accuratelyreproduced in a digital reconstruction of the patient's teeth on thecomputer.

FIG. 1 illustrates an example of a patient's physical teeth 100,according to one embodiment. For the sake of simplicity, FIG. 1 depictsa few of the patient's physical teeth 100 a, 100 b, 100 c, 100 d insteadof the entire set of the patient's physical teeth 100. As depicted inFIG. 1 , there is a space 110 between the physical teeth 100 b, 100 cthat are adjacent. According to one embodiment, at least a portion ofthe space 110 is a minimal space where the adjacent physical teeth 100b, 100 c are closest to each other. The space 110 is also referred to asan interproximal space 110 and the physical teeth 100 b, 100 c that areadjacent are also referred to as adjacent physical teeth 100 b, 100 c.The interproximal space 110 may be naturally occurring or may beartificially created. The physical teeth 100 b, 100 c have contours 130a, 130 b in the area 120. The area between the contours 130 a, 130 b ofadjacent teeth 100 b, 100 c defines the area 120 when the teeth arealigned along an arch.

When teeth are properly aligned along an arch as depicted in FIG. 1 ,the interproximal space is defined by the narrowest distance between amesial and distal surface of adjacent teeth 100 b and 100 c. However, ifan adjacent tooth is rotated, as is commonly the case when teeth are notproperly aligned, the interproximal space may be defined by thenarrowest space between any surface of two adjacent teeth (e.g., mesial,distal, buccal, lingual or more commonly a contour portion).

Sometimes dental personnel artificially create an interproximal space110 between aligned adjacent physical teeth 100 b, 100 c in order tofacilitate treatment. One way to artificially create an interproximalspace 110 is interproximal reduction. As depicted in FIG. 1 , theinterproximal space 110 is, at least in part, artificially created dueto interproximal reduction, and, therefore, the physical tooth 100 c'scontour 130 b has a flattened surface. An interproximal space 110 may beartificially created using other methods such as expansion, retraction,and moving one or more teeth, for example, to avoid extracting teethwhen the patient's jaw is too small for their teeth to fit in.

FIG. 2 illustrates an example of a digital teeth model 200 thatrepresents the patient's set of physical teeth 100 (FIG. 1 ), accordingto one embodiment. The digital teeth model 200 can be obtained with adigital scan, as described in paragraph (18) hereof. Many types ofimaging or scanning may be used to obtain a digital teeth model 200. Oneexample of an intraoral scanner that may be used is the Itero brandscanner by Cadent.

The digital teeth model 200 includes digital teeth 200 a-200 d thatrepresents each of the patient's physical teeth 100 (FIG. 1 ). Each ofthe digital teeth 200 a-200 d, according to one embodiment, representsone physical tooth 100 a-100 d. For example, digital tooth 200 arepresents physical tooth 100 a, digital tooth 200 b represents physicaltooth 100 b, digital tooth 200 c represents physical tooth 100 c, anddigital tooth 200 d represents physical tooth 100 d. The adjacentdigital teeth 200 b, 200 c respectively represent the adjacent physicalteeth 100 b, 100 c.

The current technology for obtaining a digital teeth model 200 using adigital scan, as discussed herein may not accurately depict relativelysmall interproximal spaces. Therefore, the space 110 (FIG. 1 ) betweenthe adjacent physical teeth 100 b, 100 c (FIG. 1 ) may not beproperly/accurately depicted in the digital teeth model 200. Instead,the adjacent digital teeth 200 b, 200 c (FIG. 2 ) appear to be at leastpartially connected, for example, at a location 210 in the digital teethmodel 200. As will become more evident, the holes 220, which result frommissing data, may be filled in, for example, during a cleanup processcausing the adjacent digital teeth 200 b and 200 c to appear connectedor a rough estimated interproximal gap may be created.

FIG. 3 illustrates an example of a conventional 3D virtual model 300that was created based on a digital teeth model 200, according to oneembodiment. Each of the digital teeth 300 a-300 d in the conventional 3Dvirtual model 300, according to one embodiment, represents one physicaltooth 100 a-100 d (FIG. 1 ). For example, digital tooth 300 a representsphysical tooth 100 a, digital tooth 300 b represents physical tooth 100b, digital tooth 300 c represents physical tooth 100 c, and digitaltooth 300 d represents physical tooth 100 d. The conventional 3D virtualmodel 300 includes adjacent digital teeth 300 b, 300 c that correspondto the adjacent physical teeth 100 b, 100 c (FIG. 1 ).

The conventional 3D virtual model 300 may be created by a meshingprocess. Since the space 110 (FIG. 1 ) between the adjacent physicalteeth 100 b, 100 c (FIG. 1 ) is too small for a digital scan torecognize, the adjacent digital teeth 300 b, 300 c in the digital tooth300 a-300 d model appear to be connected due to the current meshingprocess filling the holes 220 (FIG. 2 ) resulting in a filled ininterproximal space 320 between the adjacent digital teeth 300 b, 300 cof the conventional 3D virtual model 300.

FIG. 4 illustrates the use of an instrument 400 to measure aninterproximal space between adjacent physical teeth, according to oneembodiment. According to one embodiment, the instrument 400 is a pieceof metal, plastic or other material of a known thickness. The instrument400 can be inserted between the adjacent physical teeth 100 b, 100 c(FIG. 1 ). Several instruments 400 of different known thicknesses can beused. For example, instruments 400 in increments of approximately 0.1 mmmay be used. When the appropriate amount of resistance results from theinsertion of a particular instrument 400, the thickness of thatinstrument 400 can be used as the interproximal information thatrepresents the interproximal space 110 (FIG. 1 ). Each of theinstruments 400 may have a label or other indicia specifying thethickness of each of the instruments 400.

FIGS. 9 a-9 f depict scannable objects that can be inserted betweenadjacent physical teeth 100 b, 100 c and used as a part of determininginterproximal information that represents a space 110 between theadjacent physical teeth 100 b, 100 c, according to various embodiments.A digital teeth model can be created by performing a digital scan on thepatient's physical teeth 100 with a scannable object inserted snuglyinto a minimal space at the closest distance between the adjacentphysical teeth 100 b, 100 c. If physical impressions are used, theobject may be captured within the impression either as a “negative” ofthe object or as part of a “pick up” impression, whereby the objectremains physically embedded in the impression (in the same positionwhere originally placed on the teeth) when the impression is removed. Inthis regard, the object is scannable indirectly whether as a negativegeometry or as picked up via the impression. The scannable object can bedigitally removed from the digital teeth model to obtain all or a partof the interproximal information based on information related to thescannable object.

FIG. 9 a depicts scannable objects 900 a-1, 900 a-2 with a portion 910a-1, 910 a-2, that is shim shaped with different thicknesses along theshim shaped portion 910 a-1, 910 a-2. The scannable objects 900 a-1, 900a-2 also have non-shim shaped portions 920 a-1, 920 a-2.

FIG. 9 b depicts a scannable object 900B with a portion 910 b that isshim shaped with different thicknesses along the shim shaped portion 910b. Although FIGS. 9 a and 9 b depict sides of the shim shaped portions910 a-1, 910 b-2, 910 b that are symmetrical with respect to each other,various embodiments are well suited for the respective sides of the shimshaped portions 910 a-1, 910 b-2, 910 b to not be symmetrical.

FIG. 9 c depicts a scannable object 900 c that is a triodent V-wedge,according to one embodiment. The scannable object 900 c has a V shapedportion 920 c at the cross section indicated by the line, a curvedportion 930 c, and a handle 910 c. The V shaped portion 920 c, accordingto one embodiment, is a shim shaped portion with different thicknessesalong the shim shaped portion. The curved portion 930 c can be used as apart of approximating a curvature of contours associated with theadjacent physical teeth. The handle 910 c can have informationdescribing parameters associated with the scannable object 900 c, suchas the height, width, lateral curvature, base curvature, the point ofthe curvature and the radius of the curvature. The parameters can beused as a part of determining dimensional information associated with aspace 110.

FIG. 9 d depicts a scannable object 900 d that is a Triodent “fender”inserted between adjacent physical teeth, according to one embodiment.The scannable object 900 d includes a metal shim shaped portion 910 dlocated at the apex 920 d of a V shaped portion 930 d. According to oneembodiment, the V shaped portion 930 d is a shim shaped portion withdifferent thicknesses along the shim shaped portion. According to oneembodiment, the scannable object 900 d includes a curved portion 940 d.The curved portion 940 d can be used as a part of determining acurvature of contours associated with the adjacent physical teeth asdepicted in FIG. 9 d.

FIG. 9 e depicts a scannable object 900 e that has notches 910 e,according to one embodiment. FIG. 9 f depicts a scannable object 900 fthat has a shim shaped portion 910 f and a non shim shaped portion 920f, according to one embodiment. The scannable objects 900 e 900 fdepicted respectively in FIGS. 9 e and 9 f include respective indicia,such as notches 910 e or lines 930 f, that can be used for determiningone or more dimensions associated with a space 110. According to oneembodiment, the scannable object 900 c is a rigid object. According toone embodiment, any one or more of the scannable objects 900 a-900 g canbe translucent. For example, assuming that the scanning device's line ofsight is located on one side of the translucent scannable object 900a-900 g, the digital scan can at least approximate a tooth located onthe other side of the translucent scannable object 900 a-900 g. However,various embodiments are well suited for a scannable objects 900 a-900 gthat is opaque or semi-translucent, among other things.

According to one embodiment, a scannable object as depicted in FIGS. 9a-9 f can have indicia that can be used for determining one or moredimensions associated with a space 110. For example, informationpertaining to the geometry of a scannable object can be associated witha handle 910 c (FIG. 9 c ). In another example, notches 910 e (FIG. 9 e) or lines 930 f (FIG. 9 f ) can be used to determine one or moredimensions of a space 110. Examples of a dimension include but are notlimited to a width or a height associated with the space 110. Adimension may be a width associated with the minimal space based on thethickness of a portion of the scannable object. A dimension may be aheight of an interproximal area that results from interproximalreduction of at least one of the adjacent physical teeth. The indiciacan be used to determine one or more dimensions from a digital teethmodel of the set of physical teeth taken with the scannable objectinserted into the space 110, as will become more evident.

FIGS. 10 a-10 c depict scannable objects inserted between adjacentphysical teeth, according to various embodiments.

FIG. 10 a depicts several scannable objects 900 b inserted between theadjacent physical teeth to more accurately determine the shape or sizeof the respective spaces 1010 a, 1020 a, 1030 a. The spaces 1010 a, 1020a, 1030 a between various adjacent physical teeth in this illustrationare triangular shaped. Each of the scannable objects 900 b depicted inFIG. 10 a may be different sizes selected to best fit the respectivespace 1010 a, 1020 a, 1030 a that they are inserted into.

FIG. 10 b depicts a scannable object 1010 b for determining a heightassociated with a space between adjacent physical teeth. The scannableobject 1010 b has indicia 1020 b as described herein. The indicia 1020 bcan be used to determine a height 1040 b of an interproximal area 1030 bthat resulted from interproximal reduction of at least one 1050 b of theadjacent physical teeth. The indicia 1020 b can be used to determine aheight 1060 b between the top 1070 b of at least one of the adjacentphysical teeth and the papilla 1080 b of the gingival between theadjacent physical teeth.

FIG. 10 c depicts a scannable object 900 f (FIG. 9 f ) inserted betweenadjacent physical teeth that can also be used for determining adimension associated with the space between the adjacent physical teeth.For example, the scannable object 900 f can be used for determining awidth associated with the minimal space based on the thickness of aportion of the scannable object 900 f, determining a height of aninterproximal area that results from interproximal reduction of at leastone of the adjacent physical teeth, or determining a height between thetop of at least one of the adjacent physical teeth and the papilla ofthe gingiva between the adjacent physical teeth, as discussed herein.

A first digital teeth model can be created by digitally scanning the setof physical teeth with a scannable object (FIGS. 9 a-9 f ) snuglyinserted into the minimal space between the adjacent physical teeth andthe scannable object can be digitally removed from the first digitalteeth model to determine all or part of the interproximal based oninformation related to the scannable object. The scannable object can beremoved, according to one embodiment, by receiving a second digitalteeth model of the set of physical teeth of the patient without thescannable object inserted into the space and moving segmented teeth ofthe second digital teeth model to coincide with locations of the teethof the first digital model.

A scannable object (FIGS. 9 a-9 f ) can be used for determining theclosest distance between the adjacent physical teeth, a spatialorientation of the adjacent physical teeth relative to the closestdistance and the location of the closest distance. For example,referring to FIG. 10 a , the positions of the scannable objects 900 breflect the spatial orientation of the respective physical teeth thatthe scannable objects 900 b are between. The scannable objects 900 b canbe inserted snugly into the respective spaces 1010 a, 1020 a, 1030 a todetermine the locations of the closest distances between the respectiveadjacent physical teeth and to determine the spatial orientationsrelative to the closest distances.

One or more dimensions can be determined based on indicia associatedwith the scannable object (FIGS. 9 a-9 f ) in the first digital teethmodel, as discussed herein. Indicia associated with an exposed portionof the inserted scannable object can be used to determine the one ormore dimensions. Various embodiments are well suited to dimensionsbesides just width or height information. Various embodiments are wellsuited for any dimensional information that enables more accuratelymodel the space between the adjacent physical teeth. For example, thedimensional information may include shapes or sizes, or a combinationthere of, among other things, of various portions or areas of the space.The dimensional information may be three dimensional (3D) information.Scannable objects with curved shaped portions can be used to moreaccurately model curved contours and scannable objects with shim shapedportions can be used to more accurately model triangularly shapedcontours, among other things as discussed herein. The best fittingscannable object, according to one embodiment, is selected for insertionto more accurately capture one or more dimensions associated with thespace.

FIG. 5 illustrates an example of a user interface 500, according to oneembodiment. FIG. 5 is an example of a user interface 500 that isdescribed by way of illustration and not by way of limitation. Accordingto one embodiment, the user interface 500 is a part of a system thatperforms digital scans.

As illustrated in FIG. 5 , the user interface 500 depictsrepresentations of teeth. Dental personnel, such as a doctor or atechnician, can specify interproximal information using the userinterface 500. For example, the dental personnel can specify ameasurement between adjacent physical teeth, identification of theadjacent physical teeth, and identification of any physical teeth withflattened surfaces due to interproximal reduction, among other things.The adjacent physical teeth can be specified with respect to the otherphysical teeth. As depicted in FIG. 5 , adjacent physical teeth withrespective interproximal spaces between them have been specified bycircling 510 between the adjacent physical teeth. Other methods ofspecifying adjacent physical teeth can be used. For example, the name orlocation, or a combination there of can be used to specify adjacentphysical teeth. The user interface 500 may receive information that aninterproximal reduction is planned to be or has been performed on atleast one of the adjacent physical teeth.

Although the user interface 500 illustrated in FIG. 5 depictsrepresentations of teeth, various embodiments are well suited to a userinterface 500 for specifying interproximal information without depictingrepresentations of teeth. For example, other methods of specifyingadjacent physical teeth can be used. For example, the user interface mayprovide fields or drop down menus, among other things, for specifyingthe names of adjacent physical teeth or locations of adjacent physicalteeth, the amount and/or special relationship of the interproximal spaceor a combination thereof.

Alternatively or in addition to using the user interface 500, the dentalpersonnel may submit a digital or physical form specifying theappropriate information, or a subset thereof, when sending the digitalscan, for example, to a facility that creates digital tooth models,according to various embodiments. Other methods besides a user interface500, such as a form, may also be used for specifying that aninterproximal reduction is planned to be or has been performed on atleast one of the adjacent physical teeth.

The specified interproximal information can be used as a part of asegmentation process that creates digital tooth models 600 (FIG. 6 )from the digital teeth model 200 (FIG. 2 ) while maintaining theinterproximal space, according to one embodiment.

FIG. 6 illustrates an example of created digital tooth models 600,according to one embodiment. According to one embodiment, the createddigital tooth models 600 are three dimensional models of the patient'sphysical teeth 100 (FIG. 1 ). Each of the digital tooth models 600,according to one embodiment, represents one physical tooth 100 (FIG. 1). For example, digital tooth model 600 a represents physical tooth 100a, digital tooth model 600 b represents physical tooth 100 b, digitaltooth model 600 c represents physical tooth 100 c, and digital toothmodel 600 d represents physical tooth 100 d.

The digital tooth models 600 can be created based on the interproximalinformation that represents the space 110 (FIG. 1 ) between the adjacentphysical teeth 100 b, 100 c (FIG. 1 ) that correspond to the digitaltooth models 600 b, 600 c (FIG. 6 ). According to one embodiment, thedigital tooth models 600 are created as a part of segmenting the digitalteeth model 200 (FIG. 2 ) into the digital tooth models 600 whilemaintaining the interproximal space 610 (FIG. 6 ) based on theinterproximal information pertaining to a physical interproximal space110 (FIG. 1 ).

As discussed herein, with the conventional segmentation process, sincethe space 110 (FIG. 1 ) between the adjacent physical teeth 100 b, 100 c(FIG. 1 ) is too small for a digital scan to recognize, the adjacentdigital teeth 300 b, 300 c (FIG. 3 ) in the conventional threedimensional (3D) virtual model 300 (FIG. 3 ) appear to be, at leastpartially, connected due to the conventional meshing or other cleanupprocess filling the holes 2210 in the area at 210 between the adjacentdigital teeth 220 b, 200 c (FIG. 2 ). In contrast, according to variousembodiments, the segmentation process will receive interproximalinformation and will prevent filling the holes 210 (FIG. 2 ) and willuse this information to help properly create the interproximal surfacesof adjacent teeth.

The digital tooth models 600 more accurately depict the adjacentphysical teeth 100 b, 100 c (FIG. 1 ) than the digital teeth 200 b, 200c (FIG. 2 ) in the digital teeth model 200 (FIG. 2 ) due to beingcreated based on the interproximal information, according to oneembodiment. For example, since the interproximal space 110 between theadjacent physical teeth 100 b, 100 c is too small for the digital scanto recognize, the interproximal space at location 210 is not properlydepicted between the adjacent digital teeth 200 b, 200 c (FIG. 2 ) inthe digital teeth model 200 (FIG. 2 ). When a conventional 3D virtualmodel 300 (FIG. 3 ) is created from the digital teeth model 200 (FIG. 2), the adjacent digital teeth 300 b, 300 c (FIG. 3 ) in the conventional3D virtual model 300 (FIG. 3 ) appear to be connected in theinterproximal space 320 (FIG. 3 ) between the digital teeth 300 b, 300c. In contrast, according to various embodiments, interproximalinformation is obtained prior to or as part of performing thesegmentation process on the digital teeth model 200 (FIG. 2 ) tomaintain the interproximal space 610 (FIG. 6 ) between respectivelycreated digital tooth models 600 (FIG. 6 ).

Further, the exemplary created digital tooth models 600 can moreaccurately depict the contours or flattened surfaces (where IPR has beenperformed) of the area of the adjacent physical teeth. For the sake ofillustration, assume that the flattened surface (FIG. 6 ) of contour 630a (FIG. 6 ) corresponds to the flattened surface of contour 130 a (FIG.1 ) and the contours 630 a, 630 b (FIG. 6 ) correspond to the contours130 a, 130 b (FIG. 1 ). The digital tooth model 600 c can moreaccurately depict a flattened surface associated with contour 130 b ofthe corresponding physical tooth 100 c (FIG. 1 ), which was caused byinterproximal reduction on that physical tooth 100 c, than acorresponding surface associated with the digital tooth 200 c (FIG. 2 ).Further, the contours 630 a, 630 b (FIG. 6 ) more accurately depict thecontours 130 a, 130 b (FIG. 1 ) than corresponding surfaces associatedwith the digital teeth 200 b, 200 c (FIG. 2 ).

According to one embodiment, the contour of the tooth in this context is“visible contour” of the tooth when viewed from specified direction. Inparticular for the correct reconstruction of the tooth contours, thecontour is the visible contour viewed from direction perpendicular tothe dental arch and parallel to the occlusal plane. Due to possibleimprecision of a digital scan, the interproximal space 320 between theteeth 300 b and 300 c may be filled and some of the contours are missedin the vicinity of the interproximal space 320 (FIG. 3 ). According toone embodiment, the interproximal space and associated visible contoursare restored using the interproximal information that represents theinterproximal spaces as described herein. If the space is identified bythe personal as corresponding to “interproximal reduction,” then areasof the adjacent teeth can be restored on the 3D model to producestraight line contours and flat areas. If the space is identified as“natural”, then areas of the adjacent teeth can be restored on the 3Dmodel to produce natural contours and convex areas. In both cases thoughthe amount of space is equal to the distance measured on physical teeth,according to one embodiment.

The contours, if natural, can be obtained by many means including usinginformation of or from: the contours of other of the patient's teeth,based on photographs of the patient's teeth, contours of standard teeth,a database of teeth contour information, or the contours can be createdby a technician.

According to one embodiment, an elastic positioning dental appliance(also known as “an aligner”) for realigning teeth can be created basedon the created digital tooth models 600. Such an appliance may becomprised of a thin shell of elastic material that generally conforms toa patient's physical teeth but each appliance to be used at a treatmentstage has a cavity geometry that is slightly out of alignment with theteeth arrangement at the start of that treatment stage. Placement of theelastic positioning dental appliance over the physical teeth appliescontrolled forces in specific locations to gradually move the physicalteeth into a new arrangement.

A series of aligners can be used to move the physical teeth through aseries of intermediate arrangements to a final desired arrangement. Dueto the limited space within the oral cavity and extensive movements thatsome physical teeth may typically undergo for treatment, at least someof the physical teeth will often be moved throughout the series ofintermediate arrangements to properly arrange the physical teeth. Thus,a single patient treated with elastic positioning dental appliance mayexperience from 2 to over 50 stages (with an average of 25-30 alignerstages per arch) before achieving the final desired teeth arrangement.

According to one embodiment, the digital teeth model 200 (FIG. 2 ) issegmented into digital tooth models 600 (FIG. 6 ) so that the digitaltooth models 600 (FIG. 6 ) can be based on the movement of the physicalteeth 100 (FIG. 1 ) through the series of intermediate patterns due tothe course of treatment. Each of the digital tooth models 600 (FIG. 6 )may have one or more axes of its own and three dimensional (3D)coordinates so that each of the digital tooth models' 600 position canbe based on the position of a corresponding physical tooth 100 (FIG. 1 )at a given point in time, as will be described in more detail in thecontext of FIG. 11 . By moving the digital tooth models 600 (FIG. 6 ),intermediate aligners can be fabricated for each of the series ofintermediate patterns of physical teeth 100 (FIG. 1 ) movement.

Various embodiments are provided for creating one or more digital toothmodels 600 (FIG. 6 ) that more accurately depict one or more physicalteeth 100 (FIG. 1 ) based on interproximal information that representsthe interproximal space 110 (FIG. 1 ). Thus, an aligner or a series ofaligners that are created based on digital tooth models 600 (FIG. 6 )that more accurately depict the physical teeth 100 (FIG. 1 ), accordingto various embodiments, can more successfully and more easily properlyalign the teeth and close or significantly reduce or enlarge, asdesired, the interproximal spaces 110 (FIG. 1 ) between the patient'steeth 100 (FIG. 1 ).

More information pertaining to the planning and fabrication of alignersas dental appliances is described in detail in U.S. Pat. No. 5,975,893,and in published PCT application WO 98/58596 which designates the UnitedStates and which is assigned to the assignee of the present application.

FIG. 7 illustrates a system 700 for creating a digital tooth model 600(FIG. 6 ) of a patient's tooth 100 (FIG. 1 ) using interproximalinformation, according to one embodiment. The blocks that representfeatures in FIG. 7 can be arranged differently than as illustrated, andcan implement additional or fewer features than what are describedherein. Further, the features represented by the blocks in FIG. 4 can becombined in various ways. The system 700 can be implemented usinghardware, hardware and software, hardware and firmware, or a combinationthereof. According to one embodiment, the system 700 is part of a systemthat performs segmentation, as discussed herein.

The system 700 can include aninterproximal-information-obtaining-component 710, adigital-teeth-model-receiving-component 720, and adigital-tooth-model-creation-component 730. The system 700 may alsoinclude an optional physical-tooth-specification-component 712.

The interproximal-information-obtaining-component 710 is configured forreceiving interproximal information that represents a space 110 (FIG. 1) between adjacent physical teeth 100 b, 100 c (FIG. 1 ) of the patient.The space 110 (FIG. 1 ) may represent a naturally occurring spacebetween the adjacent physical teeth 100 b, 100 c or represent anartificially created space between the adjacent physical teeth 100 b,100 c.

The digital-teeth-model-receiving-component 720 is configured forreceiving a digital teeth model 200 (FIG. 2 ) of a set of physical teeth100 (FIG. 1 ) of the patient that includes the adjacent physical teeth100 b, 100 c (FIG. 1 ). The digital teeth model 200 (FIG. 2 ) can beobtained from a digital scan as described above of the set of physicalteeth 100 (FIG. 1 ).

The digital-tooth-model-creation-component 730 is configured forcreating one or more digital tooth models 600 a-600 d (FIG. 6 ) thatmore accurately depicts one or more of the physical teeth 100 (FIG. 1 )than corresponding digital teeth 200 a-200 d (FIG. 2 ) included in thedigital teeth model 200 (FIG. 2 ) based on the interproximalinformation.

The digital-tooth-model-creation-component 730 may be further configuredfor creating digital tooth models 600 b, 600 c (FIG. 6 ) representingthe adjacent physical teeth 100 b, 100 c (FIG. 1 ), which moreaccurately depict contours 130 a, 130 b (FIG. 1 ) of the adjacentphysical teeth 100 b, 100 c (FIG. 1 ) in area 120 (FIG. 1 ) between theadjacent physical teeth 100 b, 100 c (FIG. 1 ), for creating a digitaltooth model 600 c (FIG. 6 ) that more accurately depicts a flattenedsurface of contour 130 b of a physical tooth 100 c (FIG. 1 ) due tointerproximal reduction, or for creating a digital tooth model 600 c(FIG. 6 ) based on information indicating that an interproximalreduction is planned to be or has been performed on at least one of theadjacent physical teeth 100 b, 100 c (FIG. 1 ), or a combinationthereof.

The system 700 may also include a physical-tooth-specification-component712 configured for receiving information specifying which of the set ofphysical teeth 100 (FIG. 1 ) the adjacent physical teeth 100 b, 100 c(FIG. 1 ) are. According to one embodiment, the information specifyingwhich of the set of physical teeth 100 (FIG. 1 ) the adjacent physicalteeth 100 b, 100 c (FIG. 1 ) are, is a part of the interproximalinformation and may be received by theinterproximal-information-obtaining-component 710. Thephysical-tooth-specification-component 712 may be a part of theinterproximal-information-obtaining-component 710 or may communicatewith the interproximal-information-obtaining-component 710.

The system 700 can include one or more computer processors forperforming the operations of receiving of the interproximal information,the receiving of the digital teeth model 200 (FIG. 2 ) and the creatingof the one or more digital tooth models 600 (FIG. 6 ).

FIG. 8 illustrates a method of creating a digital tooth model of apatient's tooth using interproximal information, according to oneembodiment.

At 810, the method begins.

At 820, interproximal information is received that represents a space110 (FIG. 1 ) between adjacent physical teeth 100 b, 100 c (FIG. 1 ) ofthe patient. For example, an instrument 400 (FIG. 4 ) can be insertedbetween the adjacent physical teeth 100 b, 100 c (FIG. 1 ). Severalinstruments 400 of different known widths can be used. When theappropriate amount resistance results from the insertion of a particularinstrument 400, the width of that instrument 400 can be used as theinterproximal space 110 (FIG. 1 ). Each of the instruments 400 may havea label or other indicia (such as numbers, shape, colors, letters,notches, etc.), including geometric indicia, specifying the thickness ofeach of the instruments 400.

The thickness associated with the instrument 400 that providesappropriate resistance can be entered into a user interface 500 (FIG. 5). Further, the adjacent physical teeth 100 b, 100 c (FIG. 1 ) can bespecified by a user interface 500. The user interface 500 may be a partof a system that performs digital scans which may be used by a treatingprofessional, lab, service provider or manufacturer.

Various embodiments are also well suited for receiving interproximalinformation that represents a space 110 obtained, at least in part, byinserting a scannable object (FIGS. 9 a-9 f ) in the space 110, asdescribed in the context of FIGS. 9 a -10 c.

According to one embodiment, information is received that specifies theadjacent physical teeth 100 b, 100 c (FIG. 1 ) with respect to otherphysical teeth 100 a, 100 d (FIG. 1 ) associated with the set ofphysical teeth 100 (FIG. 1 ). For example, the interproximal informationcan also include identification of the adjacent teeth 100 b, 100 c (FIG.1 ) that were specified by circling 510 (FIG. 5 ) representations ofteeth displayed on a user interface 500, identifications of the adjacentteeth 100 b, 100 c (FIG. 1 ), or names of the adjacent teeth 100 b, 100c (FIG. 1 ), among other things.

The received interproximal information can represent a naturallyoccurring space 110 between the adjacent physical teeth 100 b, 100 c(FIG. 1 ) or an artificially created space 110 between the adjacentphysical teeth 100 b, 100 c (FIG. 1 ).

Information can be received indicating that an interproximal reductionis planned to be or has been performed on at least one of the adjacentphysical teeth 100 b, 100 c (FIG. 1 ). This information may be a part ofor separate from the received interproximal information.

The interproximal information, according to one embodiment, is obtainedprior to the segmentation process, for example, by a system thatperforms digital scans. The interproximal information may becommunicated to an interproximal-information-obtaining-component 710 ofthe system 700 (FIG. 7 ). The system 700 may be a part of a segmentationsystem.

At 830, a digital teeth model 200 (FIG. 2 ) of a set of physical teeth100 (FIG. 1 ) of the patient that includes the adjacent physical teeth100 b, 100 c (FIG. 1 ) is received. For example, a digital teeth model200 (FIG. 2 ) of a set of physical teeth 100 (FIG. 1 ) that includesadjacent physical teeth 100 b, 100 c (FIG. 1 ) can be received by adigital-teeth-model-receiving-component 720 of the system 700 (FIG. 7 ).

The received digital teeth model 200 (FIG. 2 ) can be derived from adigital scan of physical teeth 100 (FIG. 1 ), as described above. Theinterproximal information received at 820 may be included in a digitalteeth model 200 (FIG. 2 ) that is received at 830.

At 840, one or more digital tooth models 600 (FIG. 6 ) is created thatmore accurately depicts one or more of the physical teeth 100 a-100 d(FIG. 1 ) than corresponding digital teeth 200 a-200 d (FIG. 2 )included in the digital teeth model 200 (FIG. 2 ) based on theinterproximal information. For example, one or more digital tooth models600 a-600 d (FIG. 6 ) can be created by adigital-tooth-model-creation-component 730 of the system 700 (FIG. 7 ).The digital tooth models 600 (FIG. 6 ) can be created based on theinterproximal information that represents the space 110 (FIG. 1 )between the adjacent physical teeth 100 b, 100 c (FIG. 1 ) thatcorrespond to the digital tooth models 600 b, 600 c (FIG. 6 ).

The digital tooth models 600 b, 600 c (FIG. 6 ) more accurately depictthe adjacent physical teeth 100 b, 100 c (FIG. 1 ) than the digitalteeth 200 b, 200 c (FIG. 2 ) in the digital teeth model 200 (FIG. 2 )due to being created based on the interproximal information, accordingto one embodiment. For example, since the interproximal space 110 (FIG.1 ) between the adjacent physical teeth 100 b, 100 c (FIG. 1 ) may betoo small for a digital scan to recognize, the interproximal space 110is not properly/accurately depicted between the adjacent digital teeth200 b, 200 c (FIG. 2 ) in the digital teeth model 200 (FIG. 2 ). Thearea associated with the interproximal space 110 between the adjacentdigital teeth 200 b, 200 c (FIG. 2 ) may be, at least partially,connected with some holes 220. When a conventional 3D virtual model 300(FIG. 3 ) is created from the digital teeth model 200, the holes 220(FIG. 2 ) in the digital teeth model 200 may be filled causing theadjacent digital teeth 300 b, 300 c (FIG. 3 ) in the conventional 3Dvirtual model 300 (FIG. 3 ) to be connected in the vicinity of theinterproximal space 320 (FIG. 3 ). In contrast, according to variousembodiments, interproximal information is obtained prior to or as partof performing the segmentation process on the digital teeth model 200(FIG. 2 ) and can be used as a part of the segmentation process tomaintain the interproximal space 110 (FIG. 1 ) as depicted atinterproximal space 610 (FIG. 6 ) between respectively created digitaltooth models 600 b, 600 c (FIG. 6 ). According to one embodiment, theinterproximal space 610 is an interproximal space model.

Further, the exemplary created digital tooth models 600 (FIG. 6 ) canmore accurately depict naturally occurring or, at least partiallycreated, contours of the area of the adjacent physical teeth. Assume forthe sake of illustration that contours 630 a, 630 b (FIG. 6 ) correspondto contours 130 a, 130 b (FIG. 1 ) and that area 620 (FIG. 6 )corresponds to area 120 (FIG. 1 ). In this case, the contours 630 a, 630b (FIG. 6 ) of the digital tooth models 600 b, 600 c (FIG. 6 ) can moreaccurately depict the contours 130 a, 130 b (FIG. 1 ) of theinterproximal area 120 (FIG. 1 ) than corresponding surfaces associatedwith corresponding digital teeth 300 b, 300 c (FIG. 3 ) of theconventional 3D virtual model 300 (FIG. 3 ).

The digital tooth model 600 c (FIG. 6 ) can more accurately depict theflattened surface of the corresponding physical tooth that was caused byinterproximal reduction on that physical tooth. Assume for the sake ofillustration that the flattened surface associated with contour 630 b(FIG. 6 ) of digital model 600 c (FIG. 6 ) corresponds to the flattenedsurface associated with contour 130 b (FIG. 1 ) of the physical tooth100 c (FIG. 1 ). In this case, the flattened surface of the digitaltooth model 600 c (FIG. 6 ) can more accurately depict the flattenedsurface of the physical tooth 100 c (FIG. 1 ) than a correspondingsurface of digital tooth 300 c (FIG. 3 ) of the conventional 3D virtualmodel 300 (FIG. 3 ).

At 850, the method ends.

The receiving of the interproximal information at 820, the receiving ofthe digital teeth model at 830 and the creating of the one or moredigital tooth models at 840 can be performed, for example, by one ormore computer processors associated with a system 700 (FIG. 7 ).

According to one embodiment, a dental appliance or a series of dentalappliances can be fabricated based on the digital tooth models 600 (FIG.6 ) that more accurately depict the patient's physical teeth 100 (FIG. 1) based on the interproximal information. A dental appliance or a seriesof dental appliances that more accurately depict the patient's physicalteeth 100, according to various embodiments, can more successfully andmore easily align teeth and may close or significantly reduce orenlarge, as desired, an interproximal space 110 (FIG. 1 ) between thepatient's teeth 100 b, 100 c (FIG. 1 ).

According to one embodiment, a digital teeth model 200 (FIG. 2 ) issegmented into digital tooth models 600 a-600 d (FIG. 6 ) so that thedigital tooth models 600 a-600 d can be used as a basis for the movementof corresponding physical teeth 100 a-100 d (FIG. 1 ) through the seriesof intermediate arrangements during the course of treatment. Each of thedigital tooth models 600 a-600 d may have one or more axes of its ownand three dimensional (3D) coordinates so that each of the digital toothmodels' 600 a-600 d can be freely positioned in 3D space based on theposition of a corresponding physical tooth 100 a-100 d at a given pointin time. The 3D coordinates alone or 3D coordinates in combination withone or more axes of each of the digital tooth models 600 a-600 d can beused to match or closely approximate the position of each of thecorresponding physical teeth 100 a-100 d. Intermediate and finalaligners can be fabricated based on each of the series of intermediateand final arrangements.

For example, FIG. 11 depicts one tooth 1100 that may be used to match orclosely approximate the position of a corresponding tooth, according toone embodiment. According to one embodiment, the digital tooth 1100represents a segmented or partially segmented digital tooth, that hasone or more axes and three dimensional (3D) coordinates so that thedigital tooth 1100 can be freely positioned in 3D space. For example,the 3D coordinates x, y, and z alone or 3D coordinates x, y, and z incombination with one or more axes 1104, 1106, 1108 can be used forpositioning the digital tooth 1100.

As a frame of reference describing how a digital tooth 1100 may bemoved, an arbitrary centerline (CL) may be drawn through the digitaltooth 1600. With reference to this centerline (CL), a tooth 1100 may bemoved in orthogonal directions represented by axes 1104, 1106, and 1108(where 1104 is the centerline). The centerline may be rotated about theaxis 1108 (root angulation) and the axis 1104 (torque) as indicated byarrows 1110 and 1112, respectively. Additionally, the tooth 1100 may berotated about the centerline, as represented by an arrow 1112. Thus, allpossible free-form motions of the tooth 1100 can be performed.

Although specific operations are disclosed in flowchart 800, suchoperations are exemplary. That is, embodiments of the present inventionare well suited to performing various other operations or variations ofthe operations recited in flowchart 800. It is appreciated that theoperations in flowchart 800 can be performed in an order different thanpresented, and that not all of the operations in flowchart 800 can beperformed.

The above illustration is only provided by way of example and not by wayof limitation. There are other ways of performing the method describedby flowchart 800.

FIGS. 12A and 12B depict an example of a patient's physical teeth atvarious stages of position as a part of performing interproximalreduction, according to various embodiments. Interproximal reduction canbe used to avoid moving physical teeth along the arch to create spacefor other teeth to move (also referred to as “distillization”) orextraction of one or more physical teeth.

The patient's set of physical teeth include physical teeth 12 a-12 f.Each physical tooth 12 a-12 f has a distal and a mesial surface. Forexample, physical tooth 12 a has a distal surface a1 and mesial surfacea2, physical tooth 12 b has a distal surface b1 and mesial surface b2,physical tooth 12 c has a distal surface c1 and mesial surface c2,physical tooth 12 d has a distal surface d1 and mesial surface d2, andphysical tooth 12 e has a distal surface e1 and mesial surface e2.

The physical teeth 12 a-12 f are depicted at five different stages 90a-90 e of position. The patient's set of physical teeth 12 a-12 f aredepicted in relationship to the arch 80 and medial axis 70 of thepatient's jaw at each stage 90 a-90 e.

At the initial stage 90 a of alignment, the physical teeth 12 b, 12 c,12 d are overlapping. More specifically, the mesial surface b2 ofphysical tooth 12 b is in front of the distal surface c1 of physicaltooth 12 c, the mesial surface c2 of physical tooth 12 c is in front ofthe distal surface d1 of physical tooth 12 d.

At stage 90 b, physical teeth 12 c, 12 d are moved outwards to removethe overlapping of the physical teeth 12 b, 12 c, 12 d. As depicted, thephysical teeth 12 c, 12 d are moved by tilting them toward the patient'slips.

At stage 90 c, physical teeth 12 c, 12 d are rotated to orient themesial surface and distal surface of adjacent physical teeth 12 b, 12 c,12 d, 12 e in preparation of interproximal reduction at locations 60 a,60 b, and 60 c. More specifically as depicted in this illustration, thephysical teeth 12 c, 12 d are rotated to orient mesial surface b2 towardthe distal surface c1 for adjacent physical teeth 12 b, 12 c, the mesialsurface c2 toward the distal surface d1 for adjacent physical teeth 12c, 12 d, and the mesial surface d2 toward the distal surface e1 foradjacent physical teeth 12 d, 12 e. As can be seen, the physical teeth12 b, 12 c, 12 d, 12 e are slightly forward of the arch 80 at stage 90 cbecause the physical teeth 12 b, 12 c, 12 d, 12 e are still too large tobe moved back into the arch 80.

According to one embodiment, interproximal reduction can be performed atlocations 60 a, 60 b, and 60 c resulting in interproximal spaces 10 a,10 b, 10 c as depicted in stage 90 d. The positions of the physicalteeth 12 a-12 f are the same in stages 90 c and 90 d. The interproximalspaces 10 a, 10 b, 10 c provide sufficient room to move the physicalteeth 12 b, 12 c, 12 d, 12 e into the arch 80 and to properly align eachof the physical teeth 12 a-12 f with respect to each other as depictedin stage 90 e.

Various embodiments provide for correcting scan data of physical teethin a current position to better represent contours of physical teeth inthe vicinity of an interproximal space for treatment and possibly forperforming interproximal reduction. For example, referring to stage 90 ausing a conventional method, the triangular areas between respectiveoverlapping adjacent physical teeth 12 b, 12 c, 12 d may be filled withdata. Further, the contours of the triangular areas on the lingual sidemay appear to be closer to the tongue than is the case in reality andthe contours of the triangular areas on the buccal side may appear to becloser to the lips than is the case in reality. Further, theinterproximal spaces between the physical teeth 12 a, 12 b and 12 d and12 e may be filled in resulting in adjacent physical teeth 12 a, 12 band adjacent physical teeth 12 d and 12 e appearing to be connected.

In contrast, using various embodiments, various scannable objects asdepicted in FIGS. 9 a-9 f , can be inserted into the interproximalspaces between adjacent physical teeth and a digital scan can be taken.For example, a scannable object may be inserted between physical teeth12 c and 12 d. Due to the overlap of the adjacent physical teeth 12 cand 12 d, the scannable object may lay in an approximately flat positionon the buccal surface between physical teeth 12 c and 12 d. Thescannable object can be used as a part of extrapolating contoursassociated with the physical teeth 12 c and 12 d as discussed herein.Similarly, scannable objects can be inserted between other adjacentphysical teeth depicted in FIGS. 12A and 12B. Although the use ofvarious embodiments to better represent contours of physical teeth inthe vicinity of an interproximal space have been discussed in thecontext of physical teeth 12 a-12 f at stage 90 a, various embodimentsare well suited for better representation of contours of physical teethat other stages 90 b-90 e.

Thus, various embodiments can be used for correcting digital scan dataof physical teeth in a current position to better represent contours ofphysical teeth in the vicinity of an interproximal space between thosephysical teeth.

Any one or more of the embodiments described herein can be implementedusing non-transitory computer readable storage medium andcomputer-executable instructions which reside, for example, incomputer-readable storage medium of a computer system or like device.The non-transitory computer readable storage medium can be any kind ofmemory that instructions can be stored on. Examples of thenon-transitory computer readable storage medium include but are notlimited to a disk, a compact disk (CD), a digital versatile device(DVD), read only memory (ROM), flash, and so on. As described above,certain processes and operations of various embodiments of the presentinvention are realized, in one embodiment, as a series of instructions(e.g., software program) that reside within non-transitory computerreadable storage memory of a computer system and are executed by thecomputer processor of the computer system. When executed, theinstructions cause the computer system to implement the functionality ofvarious embodiments of the present invention. According to oneembodiment, the non-transitory computer readable storage medium istangible.

According to one embodiment, a non-transitory computer readable storagemedium having computer-executable instructions stored thereon forcausing a computer system to perform a method of creating a digitaltooth model of a patient's tooth using interproximal information isprovided. For example, interproximal information is received thatrepresents a space 110 (FIG. 1 ) between adjacent physical teeth 100 b,100 c (FIG. 1 ) associated with a set of physical teeth 100 (FIG. 1 ).The space 110 can be a naturally occurring space between the adjacentphysical teeth or an artificially created space. Interproximalinformation can be determined by manually inserting pieces of material,which each have a different thickness, between the adjacent physicalteeth 100 b, 100 c (FIG. 4 ). User specified information specifying theadjacent physical teeth 100 b, 100 c (FIG. 1 ) with respect to otherphysical teeth 100 a, 100 d (FIG. 1 ) associated with the set ofphysical teeth 100 (FIG. 1 ) can be received. The received userspecified information can be specified by a circle 510 (FIG. 5 ) aroundvisual representations of the adjacent physical teeth 100 b, 100 c (FIG.1 ), identification information of the adjacent physical teeth 100 b,100 c (FIG. 1 ), or locations of the adjacent physical teeth 100 b, 100c (FIG. 1 ), or a combination thereof.

Further, according to one embodiment, the non-transitory computerreadable storage medium provides for the creation of digital toothmodels 600 b, 600 c (FIG. 6 ) that more accurately depict the adjacentphysical teeth 100 b, 100 c (FIG. 1 ) than corresponding digital teeth200 b, 200 c (FIG. 2 ) included in a digital teeth model 200 (FIG. 2 )based on the interproximal information, according to one embodiment. Forexample, one or more digital tooth models 600 (FIG. 6 ) can be createdthat include adjacent digital tooth models 600 b, 600 c (FIG. 6 ) thatmore accurately depict contours 130 a, 130 b (FIG. 1 ) of the adjacentphysical teeth 100 b, 100 c (FIG. 1 ). An area associated with theinterproximal space 110 (FIG. 2 ) of the digital teeth model 200 (FIG. 2) that corresponds to the space 110 (FIG. 1 ) between the adjacentphysical teeth 100 b, 100 c (FIG. 1 ) can be identified and a digitaltooth model 600 b, 600 c (FIG. 6 ) can be created that represents one ofthe adjacent physical teeth 100 b, 100 c (FIG. 1 ) by preventing thedigital tooth model 600 b, 600 c (FIG. 6 ) from extending into an area610 (FIG. 6 ).

Creating digital tooth models 600 (FIG. 6 ) of a patient's teeth 100(FIG. 1 ) using interproximal information which enables more accuratedigital tooth models at least provides, for example, improved fittingdental appliance, improved treatment outcome, improved closure oropening of interproximal spaces, more confidence for the dentalpersonnel, and the ability to better track interproximal space closurefrom a research and development stand point.

Example embodiments of the subject matter are thus described. Althoughthe subject matter has been described in a language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

Various embodiments have been described in various combinations andillustrations. However, any two or more embodiments or features may becombined. Further, any embodiment or feature may be used separately fromany other embodiment or feature. Phrases, such as “an embodiment,” “oneembodiment,” among others, used herein, are not necessarily referring tothe same embodiment. Features, structures, or characteristics of anyembodiment may be combined in any suitable manner with one or more otherfeatures, structures, or characteristics.

What is claimed is:
 1. A method of generating a digital dental model ofa patient's teeth, the method comprising: receiving, by adigital-teeth-model-receiving-component, a first digital scan of thepatient's teeth, wherein the first digital scan comprises a firstthree-dimensional digital teeth model; receiving, by thedigital-teeth-model-receiving-component, a second digital scan of thepatient's teeth, wherein the second digital scan comprises a scannableobject inserted in an interproximal space between a first tooth and asecond tooth of the patient's teeth, wherein dimensions of theinterproximal space cannot be determined from the first digital scan;determining, by an interproximal-information-obtaining-component,interproximal information of the patient's teeth, wherein theinterproximal information is based at least in part on the seconddigital scan, and wherein the interproximal information comprises adistance of the interproximal space between the first tooth and thesecond tooth of the patient's teeth; and generating, by adigital-teeth-model-creation-component, a modified three-dimensionaldigital teeth model based at least in part on the firstthree-dimensional digital teeth model and the interproximal information,wherein the modified three-dimensional digital teeth model is generatedby digitally removing, from the first three-dimensional digital teethmodel, three-dimensional model portions corresponding to theinterproximal space between the first tooth and the second tooth of thepatient, thereby providing a depiction of the interproximal spacebetween the first tooth and the second tooth of the patient's teeth. 2.The method of generating the digital dental model of claim 1, whereinthe scannable object comprises a known thickness.
 3. The method ofgenerating the digital dental model of claim 1, wherein the scannableobject comprises indicia to determine the distance of the interproximalspace between the first tooth and the second tooth of the patient'steeth.
 4. The method of generating the digital dental model of claim 1,wherein the interproximal information is based at least in part oninformation received through a user interface.
 5. The method ofgenerating the digital dental model of claim 4, wherein the userinterface is configured to receive an input from a dental personnelrelated to the distance of the interproximal space between the firsttooth and the second tooth of the patient's teeth.
 6. The method ofgenerating the digital dental model of claim 4, wherein the userinterface is configured to provide a visual representation of theinterproximal space between the first tooth and the second tooth of thepatient's teeth.
 7. The method of generating the digital dental model ofclaim 1, the method further comprising receiving information indicatingthat interproximal reduction is planned to be or has been performed onthe first tooth and the second tooth of the patient's teeth.
 8. Themethod of generating the digital dental model of claim 1, whereingenerating the modified three-dimensional digital teeth model comprisessegmenting the first three-dimensional digital teeth model based atleast in part on the interproximal information.
 9. The method ofgenerating the digital dental model of claim 8, wherein the modifiedthree-dimensional digital teeth model comprises a plurality of digitaltooth models.
 10. The method of generating the digital dental model ofclaim 1, wherein generating the modified three-dimensional digital teethmodel comprises depicting contours of areas between the first tooth andthe second tooth of the patient's teeth.
 11. The method of generatingthe digital dental model of claim 1, wherein the interproximalinformation represents a naturally occurring interproximal space betweenthe first tooth and the second tooth of the patient's teeth.
 12. Themethod of generating the digital dental model of claim 1, wherein theinterproximal information represents an artificially createdinterproximal space between the first tooth and the second tooth of thepatient's teeth.
 13. The method of generating the digital dental modelof claim 1, wherein the modified three-dimensional digital teeth modelcomprises one or more flattened surfaces for representing at least aportion of the first tooth or the second tooth near the interproximalspace.
 14. A system for creating a digital dental model of a patient'steeth, the system comprising: a digital-teeth-model-receiving-component,wherein the digital-teeth-model-receiving-component is configured toreceive 1) a first digital scan of the patient's teeth, wherein thefirst digital scan comprises a first three-dimensional digital teethmodel, and 2) a second digital scan of the patient's teeth, wherein thesecond digital scan comprises a scannable object inserted in aninterproximal space between a first tooth and a second tooth of thepatient's teeth, wherein dimensions of the interproximal space cannot bedetermined from the first digital scan; aninterproximal-information-obtaining-component in association with thedigital-teeth-model-receiving-component, wherein theinterproximal-information-obtaining-component is configured to determineinterproximal information of the patient's teeth, wherein theinterproximal information is based at least in part on the seconddigital scan, and wherein the interproximal information comprises adistance of the interproximal space between the first tooth and thesecond tooth of the patient's teeth; adigital-teeth-model-creation-component in association with thedigital-teeth-model-receiving-component and theinterproximal-information-obtaining-component, wherein thedigital-teeth-model-creation-component is configured to generate amodified three-dimensional digital teeth model based at least in part onthe first three-dimensional digital teeth model and the interproximalinformation, wherein the modified three-dimensional digital teeth modelis generated by digitally removing, from the first three-dimensionaldigital teeth model, three-dimensional model portions corresponding tothe interproximal space between the first tooth and the second tooth ofthe patient, thereby providing a depiction of the interproximal spacebetween the first tooth and the second tooth of the patient's teeth. 15.The system for creating the digital dental model of claim 14, whereinthe scannable object comprises a known thickness.
 16. The system forcreating the digital dental model of claim 14, wherein the scannableobject comprises indicia to determine the distance of the interproximalspace between the first tooth and the second tooth of the patient'steeth.
 17. The system for creating the digital dental model of claim 14,the system further comprising a user interface, wherein theinterproximal information is based at least in part on informationreceived through the user interface.
 18. The system for creating thedigital dental model of claim 17, wherein the user interface isconfigured to receive an input from a dental personnel related to thedistance of the interproximal space between the first tooth and thesecond tooth of the patient's teeth.
 19. The system for creating thedigital dental model of claim 17, wherein the user interface isconfigured to provide a visual representation of the interproximal spacebetween the first tooth and the second tooth of the patient's teeth. 20.The system for creating the digital dental model of claim 14, whereinthe system is configured to receive information indicating thatinterproximal reduction is planned to be or has been performed on thefirst tooth and the second tooth of the patient's teeth.
 21. The systemfor creating the digital dental model of claim 14, wherein thedigital-teeth-model-creation-component is further configured to segmentthe first three-dimensional digital teeth model based at least in parton the interproximal information.
 22. The system for creating thedigital dental model of claim 21, wherein the modified three-dimensionaldigital teeth model comprises a plurality of digital tooth models. 23.The system for creating the digital dental model of claim 14, whereinthe digital-teeth-model-creation-component is further configured todepict contours of areas between the first tooth and the second tooth ofthe patient's teeth.
 24. The system for creating the digital dentalmodel of claim 14, wherein the interproximal information represents anaturally occurring interproximal space between the first tooth and thesecond tooth of the patient's teeth.
 25. The system for creating thedigital dental model of claim 14, wherein the interproximal informationrepresents an artificially created interproximal space between the firsttooth and the second tooth of the patient's teeth.
 26. The system forcreating the digital dental model of claim 14, wherein the modifiedthree-dimensional digital teeth model comprises one or more flattenedsurfaces for representing at least a portion of the first tooth or thesecond tooth near the interproximal space.